I have been using Karen's recipe for over a year and have NEVER had a problem with them spreading as there is no baking powder in them. Well I've made 3 batches of dough so far and each one keeps producing cookies that are spreading like crazy!

Does anyone know any other reasons why this could be happening? My pans are cold and so is the dough before they go into the oven.

I've never used that recipe, so I'm not sure what's in it...but I've noticed that I have problems with my roll-out cookie recipe when I use margarine that has less trans-fat than the one I usually use. I always use Imperial but I bought Blue Bonnet because it was on sale, and my cookies spread like crazy, so I checked the labels and was amazed how much difference there could really be between brands.

I've only used unsalted butter and it's always worked fine.

Hmmm...her recipies are great and never seem to spread. Not sure if this could be an issue, but have you checked your oven tempature with a thermometer lately to make sure the temp is still accurate. Sorry couldn't be of more help! Good luck.